The invention relates to a method of manufacturing a dynamic groove bearing having an internal bearing part which is arranged coaxially relative to an external bearing part, which bearing parts are rotatable relative to one another and experience at least an axial bearing force during this, by which method the bearing parts are provided with cooperating bearing surfaces, the bearing surface of one of the bearing parts being provided by means of a press tool and one of the bearing surfaces being provided with a pattern of grooves.
The invention also relates to a die suitable for use in a method according to the invention.
The invention also relates to a housing manufactured by a method according to the invention.
The invention also relates to a bearing part manufactured by a method according to the invention.
The invention also relates to a data storage unit comprising an information disc and a scanning unit for cooperating with the information disc, which disc is rotatably supported in a cassette-shaped housing by means of two dynamic groove bearings manufactured by a method according to the invention.
The invention also relates to a method of manufacturing a rotatable scanning unit with a base drum which has an outer wall with a helical magnetic tape guide and a scanning drum which is rotatable relative to the base drum and which has at least one magnetic head, which scanning unit is provided with dynamic groove bearing by a method according to the invention.
Finally, the invention also relates to a magnetic tape device provided with a rotatable scanning unit manufactured by a method according to the invention.
A method of the kind mentioned in the opening paragraph for manufacturing a dynamic groove bearing is known from German Patent Application 22 09 712. In the known method, the press tool comprises a smooth press ball by which a smooth bearing surface with the shape of a sphere segment is pressed into the external bearing part. The internal bearing part is provided with a metal bearing ball, the difference between the radius of the press ball and the radius of the bearing ball being equal to a desired bearing gap height. An accurate bearing gap height is thus provided. The pattern of grooves is provided on the bearing ball in a manner not described in the said Patent Application.
A disadvantage of the known method is that the application of an accurate pattern of grooves on the bearing ball used in the groove bearing by means of, for example, a machining operation or an etching process is time-consuming. As a result, the manufacture of large numbers of groove bearings by the known method is laborious. In addition, the press ball used in the known method must be replaced already after the manufacture of one single groove bearing.